a. Field of the Invention
The instant invention relates to the collection of data regarding a patient, such as geometric data regarding a portion of the patient's anatomy, using a localization system. In particular, the instant invention relates to methods and systems for processing a localization signal that describes the position, and optionally the orientation, of a device within the localization field to account for signal artifacts attributable to patient respiration.
b. Background Art
It is well known how to generate heart chamber geometry in preparation for cardiac diagnostic or therapeutic procedures. Often, a mapping catheter is introduced into the heart chamber of interest and moved around within the heart chamber, either randomly, pseudo-randomly, or according to one or more preset patterns. The three-dimensional coordinates are measured using a localization system (sometimes also referred to as a “mapping system,” “navigation system,” or “positional feedback system”). The localization system measures the coordinates of the mapping catheter within a localization field, typically by relating a characteristic of the localization field, such as a voltage, experienced by the mapping catheter to a location of the catheter within the field.
Localization signals produced by localization systems often exhibit noise. One prevalent source of noise is patient respiration. Patient respiration may introduce noise by moving the generators and/or references for the localization field or by changing the patient's biological characteristics (e.g., impedance). Thus, an electrode within the localization field that is, in fact, stationary may appear to be moving.